// DEMO7_13.CPP 8-bit blitting demo

// INCLUDES ///////////////////////////////////////////////

#define WIN32_LEAN_AND_MEAN  // just say no to MFC

#define INITGUID

#include <windows.h>   // include important windows stuff
#include <windowsx.h> 
#include <mmsystem.h>
#include <iostream> // include important C/C++ stuff
#include <conio.h>
#include <stdlib.h>
#include <malloc.h>
#include <memory.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h> 
#include <math.h>
#include <io.h>
#include <fcntl.h>

#include <ddraw.h> // include directdraw

// DEFINES ////////////////////////////////////////////////

// defines for windows 
#define WINDOW_CLASS_NAME L"WINCLASS1"

// default screen size
#define SCREEN_WIDTH    640  // size of screen
#define SCREEN_HEIGHT   480
#define SCREEN_BPP      8    // bits per pixel

#define BITMAP_ID            0x4D42 // universal id for a bitmap
#define MAX_COLORS_PALETTE   256

// TYPES //////////////////////////////////////////////////////

// basic unsigned types
typedef unsigned short USHORT;
typedef unsigned short WORD;
typedef unsigned char  UCHAR;
typedef unsigned char  BYTE;

// container structure for bitmaps .BMP file
typedef struct BITMAP_FILE_TAG
{
	BITMAPFILEHEADER bitmapfileheader;  // this contains the bitmapfile header
	BITMAPINFOHEADER bitmapinfoheader;  // this is all the info including the palette
	PALETTEENTRY     palette[256];      // we will store the palette here
	UCHAR            *buffer;           // this is a pointer to the data

} BITMAP_FILE, *BITMAP_FILE_PTR;

// this will hold our little alien
typedef struct ALIEN_OBJ_TYP
{
	LPDIRECTDRAWSURFACE7 frames[3]; // 3 frames of animation for complete walk cycle
	int x, y;                        // position of alien
	int velocity;                   // x-velocity
	int current_frame;              // current frame of animation
	int counter;                    // used to time animation

} ALIEN_OBJ, *ALIEN_OBJ_PTR;

// PROTOTYPES  //////////////////////////////////////////////

int Flip_Bitmap(UCHAR *image, int bytes_per_line, int height);

int Load_Bitmap_File(BITMAP_FILE_PTR bitmap, char *filename);

int Unload_Bitmap_File(BITMAP_FILE_PTR bitmap);

int DDraw_Fill_Surface(LPDIRECTDRAWSURFACE7 lpdds, int color);

int Scan_Image_Bitmap(BITMAP_FILE_PTR bitmap, LPDIRECTDRAWSURFACE7 lpdds, int cx, int cy);

LPDIRECTDRAWSURFACE7 DDraw_Create_Surface(int width, int height, int mem_flags, int color_key);

int DDraw_Draw_Surface(LPDIRECTDRAWSURFACE7 source, int x, int y,
	int width, int height, LPDIRECTDRAWSURFACE7 dest,
	int transparent);

LPDIRECTDRAWCLIPPER DDraw_Attach_Clipper(LPDIRECTDRAWSURFACE7 lpdds,
	int num_rects,
	LPRECT clip_list);

int Draw_Text_GDI(char *text, int x, int y, COLORREF color, LPDIRECTDRAWSURFACE7 lpdds);

// MACROS /////////////////////////////////////////////////

// tests if a key is up or down
#define KEYDOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
#define KEYUP(vk_code)   ((GetAsyncKeyState(vk_code) & 0x8000) ? 0 : 1)

// initializes a direct draw struct
#define DDRAW_INIT_STRUCT(ddstruct) { memset(&ddstruct,0,sizeof(ddstruct)); ddstruct.dwSize=sizeof(ddstruct); }

// GLOBALS ////////////////////////////////////////////////

HWND      main_window_handle = NULL; // globally track main window
int       window_closed = 0;    // tracks if window is closed
HINSTANCE hinstance_app = NULL; // globally track hinstance

// directdraw stuff

LPDIRECTDRAW7         lpdd = NULL;   // dd4 object
LPDIRECTDRAWSURFACE7  lpddsprimary = NULL;   // dd primary surface
LPDIRECTDRAWSURFACE7  lpddsback = NULL;   // dd back surface
LPDIRECTDRAWPALETTE   lpddpal = NULL;   // a pointer to the created dd palette
LPDIRECTDRAWCLIPPER   lpddclipper = NULL;   // dd clipper
PALETTEENTRY          palette[256];          // color palette
PALETTEENTRY          save_palette[256];     // used to save palettes
DDSURFACEDESC2        ddsd;                  // a direct draw surface description struct
DDBLTFX               ddbltfx;               // used to fill
DDSCAPS2              ddscaps;               // a direct draw surface capabilities struct
HRESULT               ddrval;                // result back from dd calls
DWORD                 start_clock_count = 0; // used for timing

BITMAP_FILE           bitmap;                // holds the bitmap

ALIEN_OBJ             aliens[3];             // 3 aliens, one on each level

LPDIRECTDRAWSURFACE7  lpddsbackground = NULL;// this will hold the background image

char buffer[80];                             // general printing buffer

int gwidth = -1;
int gheight = -1;

// FUNCTIONS ////////////////////////////////////////////////

int Load_Bitmap_File(BITMAP_FILE_PTR bitmap, char *filename)
{
	// this function opens a bitmap file and loads the data into bitmap

	int file_handle,  // the file handle
		index;        // looping index

	UCHAR   *temp_buffer = NULL; // used to convert 24 bit images to 16 bit
	OFSTRUCT file_data;          // the file data information

	// open the file if it exists
	if ((file_handle = OpenFile(filename, &file_data, OF_READ)) == -1)
		return(0);

	// now load the bitmap file header
	_lread(file_handle, &bitmap->bitmapfileheader, sizeof(BITMAPFILEHEADER));

	// test if this is a bitmap file
	if (bitmap->bitmapfileheader.bfType != BITMAP_ID)
	{
		// close the file
		_lclose(file_handle);

		// return error
		return(0);
	} // end if

 // now we know this is a bitmap, so read in all the sections

 // first the bitmap infoheader

 // now load the bitmap file header
	_lread(file_handle, &bitmap->bitmapinfoheader, sizeof(BITMAPINFOHEADER));

	// now load the color palette if there is one
	if (bitmap->bitmapinfoheader.biBitCount == 8)
	{
		_lread(file_handle, &bitmap->palette, MAX_COLORS_PALETTE * sizeof(PALETTEENTRY));

		// now set all the flags in the palette correctly and fix the reversed 
		// BGR RGBQUAD data format
		for (index = 0; index < MAX_COLORS_PALETTE; index++)
		{
			// reverse the red and green fields
			int temp_color = bitmap->palette[index].peRed;
			bitmap->palette[index].peRed = bitmap->palette[index].peBlue;
			bitmap->palette[index].peBlue = temp_color;

			// always set the flags word to this
			bitmap->palette[index].peFlags = PC_NOCOLLAPSE;
		} // end for index

	} // end if

// finally the image data itself
	_llseek(file_handle, -(int)(bitmap->bitmapinfoheader.biSizeImage), SEEK_END);

	// now read in the image, if the image is 8 or 16 bit then simply read it
	// but if its 24 bit then read it into a temporary area and then convert
	// it to a 16 bit image

	if (bitmap->bitmapinfoheader.biBitCount == 8 || bitmap->bitmapinfoheader.biBitCount == 16 ||
		bitmap->bitmapinfoheader.biBitCount == 24)
	{
		// delete the last image if there was one
		if (bitmap->buffer)
			free(bitmap->buffer);

		// allocate the memory for the image
		if (!(bitmap->buffer = (UCHAR *)malloc(bitmap->bitmapinfoheader.biSizeImage)))
		{
			// close the file
			_lclose(file_handle);

			// return error
			return(0);
		} // end if

	 // now read it in
		_lread(file_handle, bitmap->buffer, bitmap->bitmapinfoheader.biSizeImage);

	} // end if
	else
	{
		// serious problem
		return(0);

	} // end else

#if 0
// write the file info out 
	printf("\nfilename:%s \nsize=%d \nwidth=%d \nheight=%d \nbitsperpixel=%d \ncolors=%d \nimpcolors=%d",
		filename,
		bitmap->bitmapinfoheader.biSizeImage,
		bitmap->bitmapinfoheader.biWidth,
		bitmap->bitmapinfoheader.biHeight,
		bitmap->bitmapinfoheader.biBitCount,
		bitmap->bitmapinfoheader.biClrUsed,
		bitmap->bitmapinfoheader.biClrImportant);
#endif

	// close the file
	_lclose(file_handle);

	// flip the bitmap
	Flip_Bitmap(bitmap->buffer,
		bitmap->bitmapinfoheader.biWidth*(bitmap->bitmapinfoheader.biBitCount / 8),
		bitmap->bitmapinfoheader.biHeight);

	// return success
	return(1);

} // end Load_Bitmap_File

///////////////////////////////////////////////////////////

int Unload_Bitmap_File(BITMAP_FILE_PTR bitmap)
{
	// this function releases all memory associated with "bitmap"
	if (bitmap->buffer)
	{
		// release memory
		free(bitmap->buffer);

		// reset pointer
		bitmap->buffer = NULL;

	} // end if

 // return success
	return(1);

} // end Unload_Bitmap_File

///////////////////////////////////////////////////////////

int Flip_Bitmap(UCHAR *image, int bytes_per_line, int height)
{
	// this function is used to flip bottom-up .BMP images

	UCHAR *buffer; // used to perform the image processing
	int index;     // looping index

	// allocate the temporary buffer
	if (!(buffer = (UCHAR *)malloc(bytes_per_line*height)))
		return(0);

	// copy image to work area
	memcpy(buffer, image, bytes_per_line*height);

	// flip vertically
	for (index = 0; index < height; index++)
		memcpy(&image[((height - 1) - index)*bytes_per_line],
			&buffer[index*bytes_per_line], bytes_per_line);

	// release the memory
	free(buffer);

	// return success
	return(1);

} // end Flip_Bitmap

///////////////////////////////////////////////////////////////

LPDIRECTDRAWCLIPPER DDraw_Attach_Clipper(LPDIRECTDRAWSURFACE7 lpdds,
	int num_rects,
	LPRECT clip_list)

{
	// this function creates a clipper from the sent clip list and attaches
	// it to the sent surface

	int index;                         // looping var
	LPDIRECTDRAWCLIPPER lpddclipper;   // pointer to the newly created dd clipper
	LPRGNDATA region_data;             // pointer to the region data that contains
									   // the header and clip list

	// first create the direct draw clipper
	if (FAILED(lpdd->CreateClipper(0, &lpddclipper, NULL)))
		return(NULL);

	// now create the clip list from the sent data

	// first allocate memory for region data
	region_data = (LPRGNDATA)malloc(sizeof(RGNDATAHEADER) + num_rects * sizeof(RECT));

	// now copy the rects into region data
	memcpy(region_data->Buffer, clip_list, sizeof(RECT)*num_rects);

	// set up fields of header
	region_data->rdh.dwSize = sizeof(RGNDATAHEADER);
	region_data->rdh.iType = RDH_RECTANGLES;
	region_data->rdh.nCount = num_rects;
	region_data->rdh.nRgnSize = num_rects * sizeof(RECT);

	region_data->rdh.rcBound.left = 64000;
	region_data->rdh.rcBound.top = 64000;
	region_data->rdh.rcBound.right = -64000;
	region_data->rdh.rcBound.bottom = -64000;

	// find bounds of all clipping regions
	for (index = 0; index < num_rects; index++)
	{
		// test if the next rectangle unioned with the current bound is larger
		if (clip_list[index].left < region_data->rdh.rcBound.left)
			region_data->rdh.rcBound.left = clip_list[index].left;

		if (clip_list[index].right > region_data->rdh.rcBound.right)
			region_data->rdh.rcBound.right = clip_list[index].right;

		if (clip_list[index].top < region_data->rdh.rcBound.top)
			region_data->rdh.rcBound.top = clip_list[index].top;

		if (clip_list[index].bottom > region_data->rdh.rcBound.bottom)
			region_data->rdh.rcBound.bottom = clip_list[index].bottom;

	} // end for index

// now we have computed the bounding rectangle region and set up the data
// now let's set the clipping list

	if (FAILED(lpddclipper->SetClipList(region_data, 0)))
	{
		// release memory and return error
		free(region_data);
		return(NULL);
	} // end if

 // now attach the clipper to the surface
	if (FAILED(lpdds->SetClipper(lpddclipper)))
	{
		// release memory and return error
		free(region_data);
		return(NULL);
	} // end if

 // all is well, so release memory and send back the pointer to the new clipper
	free(region_data);
	return(lpddclipper);

} // end DDraw_Attach_Clipper

///////////////////////////////////////////////////////////   

int DDraw_Fill_Surface(LPDIRECTDRAWSURFACE7 lpdds, int color)
{
	DDBLTFX ddbltfx; // this contains the DDBLTFX structure

	// clear out the structure and set the size field 
	DDRAW_INIT_STRUCT(ddbltfx);

	// set the dwfillcolor field to the desired color
	ddbltfx.dwFillColor = color;

	// ready to blt to surface
	lpdds->Blt(NULL,       // ptr to dest rectangle
		NULL,       // ptr to source surface, NA            
		NULL,       // ptr to source rectangle, NA
		DDBLT_COLORFILL | DDBLT_WAIT,   // fill and wait                   
		&ddbltfx);  // ptr to DDBLTFX structure

// return success
	return(1);
} // end DDraw_Fill_Surface

///////////////////////////////////////////////////////////////

int DDraw_Draw_Surface(LPDIRECTDRAWSURFACE7 source, // source surface to draw
	int x, int y,                 // position to draw at
	int width, int height,        // size of source surface
	LPDIRECTDRAWSURFACE7 dest,    // surface to draw the surface on
	int transparent = 1)          // transparency flag
{
	// draw a bob at the x,y defined in the BOB
	// on the destination surface defined in dest

	RECT dest_rect,   // the destination rectangle
		source_rect; // the source rectangle                             

   // fill in the destination rect
	dest_rect.left = x;
	dest_rect.top = y;
	dest_rect.right = x + width - 1;
	dest_rect.bottom = y + height - 1;

	// fill in the source rect
	source_rect.left = 0;
	source_rect.top = 0;
	source_rect.right = width - 1;
	source_rect.bottom = height - 1;

	// test transparency flag

	if (transparent)
	{
		// enable color key blit
		// blt to destination surface
		if (FAILED(dest->Blt(&dest_rect, source,
			&source_rect, (DDBLT_WAIT | DDBLT_KEYSRC),
			NULL)))
			return(0);

	} // end if
	else
	{
		// perform blit without color key
		// blt to destination surface
		if (FAILED(dest->Blt(&dest_rect, source,
			&source_rect, (DDBLT_WAIT),
			NULL)))
			return(0);

	} // end if

 // return success
	return(1);

} // end DDraw_Draw_Surface

///////////////////////////////////////////////////////////////

int Scan_Image_Bitmap(BITMAP_FILE_PTR bitmap,     // bitmap file to scan image data from
	LPDIRECTDRAWSURFACE7 lpdds, // surface to hold data
	int cx, int cy)             // cell to scan image from
{
	// this function extracts a bitmap out of a bitmap file

	UCHAR *source_ptr,   // working pointers
		*dest_ptr;

	DDSURFACEDESC2 ddsd;  //  direct draw surface description 

	// get the addr to destination surface memory

	// set size of the structure
	ddsd.dwSize = sizeof(ddsd);

	// lock the display surface
	lpdds->Lock(NULL,
		&ddsd,
		DDLOCK_WAIT | DDLOCK_SURFACEMEMORYPTR,
		NULL);

	// compute position to start scanning bits from
	cx = cx*(ddsd.dwWidth + 1) + 1;
	cy = cy*(ddsd.dwHeight + 1) + 1;

	gwidth = ddsd.dwWidth;
	gheight = ddsd.dwHeight;

	// extract bitmap data
	source_ptr = bitmap->buffer + cy*bitmap->bitmapinfoheader.biWidth + cx;

	// assign a pointer to the memory surface for manipulation
	dest_ptr = (UCHAR *)ddsd.lpSurface;

	// iterate thru each scanline and copy bitmap
	for (int index_y = 0; index_y < ddsd.dwHeight; index_y++)
	{
		// copy next line of data to destination
		memcpy(dest_ptr, source_ptr, ddsd.dwWidth);

		// advance pointers
		dest_ptr += (ddsd.lPitch); // (ddsd.dwWidth);
		source_ptr += bitmap->bitmapinfoheader.biWidth;
	} // end for index_y

// unlock the surface 
	lpdds->Unlock(NULL);

	// return success
	return(1);

} // end Scan_Image_Bitmap

///////////////////////////////////////////////////////////////

LPDIRECTDRAWSURFACE7 DDraw_Create_Surface(int width, int height, int mem_flags, int color_key = 0)
{
	// this function creates an offscreen plain surface

	DDSURFACEDESC2 ddsd;         // working description
	LPDIRECTDRAWSURFACE7 lpdds;  // temporary surface

	// set to access caps, width, and height
	memset(&ddsd, 0, sizeof(ddsd));
	ddsd.dwSize = sizeof(ddsd);
	ddsd.dwFlags = DDSD_CAPS | DDSD_WIDTH | DDSD_HEIGHT;

	// set dimensions of the new bitmap surface
	ddsd.dwWidth = width;
	ddsd.dwHeight = height;

	// set surface to offscreen plain
	ddsd.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN | mem_flags;

	// create the surface
	if (FAILED(lpdd->CreateSurface(&ddsd, &lpdds, NULL)))
		return(NULL);

	// test if user wants a color key
	if (color_key >= 0)
	{
		// set color key to color 0
		DDCOLORKEY color_key; // used to set color key
		color_key.dwColorSpaceLowValue = 0;
		color_key.dwColorSpaceHighValue = 0;

		// now set the color key for source blitting
		lpdds->SetColorKey(DDCKEY_SRCBLT, &color_key);
	} // end if

 // return surface
	return(lpdds);
} // end DDraw_Create_Surface


///////////////////////////////////////////////////////////////

LRESULT CALLBACK WindowProc(HWND hwnd,
	UINT msg,
	WPARAM wparam,
	LPARAM lparam)
{
	// this is the main message handler of the system
	PAINTSTRUCT		ps;		// used in WM_PAINT
	HDC				hdc;	// handle to a device context
	char buffer[80];        // used to print strings

	// what is the message 
	switch (msg)
	{
	case WM_CREATE:
	{
		// do initialization stuff here
		// return success
		return(0);
	} break;

	case WM_PAINT:
	{
		// simply validate the window 
		hdc = BeginPaint(hwnd, &ps);

		// end painting
		EndPaint(hwnd, &ps);

		// return success
		return(0);
	} break;

	case WM_DESTROY:
	{

		// kill the application, this sends a WM_QUIT message 
		PostQuitMessage(0);

		// return success
		return(0);
	} break;

	default:break;

	} // end switch

// process any messages that we didn't take care of 
	return (DefWindowProc(hwnd, msg, wparam, lparam));

} // end WinProc

///////////////////////////////////////////////////////////

int Draw_Text_GDI(char *text, int x, int y, COLORREF color, LPDIRECTDRAWSURFACE7 lpdds)
{
	// this function draws the sent text on the sent surface 
	// using color index as the color in the palette

	HDC xdc; // the working dc

	// get the dc from surface
	if (FAILED(lpdds->GetDC(&xdc)))
		return(0);

	// set the colors for the text up
	SetTextColor(xdc, color);

	// set background mode to transparent so black isn't copied
	SetBkMode(xdc, TRANSPARENT);

	// draw the text a
	TextOutA(xdc, x, y, text, strlen(text));

	// release the dc
	lpdds->ReleaseDC(xdc);

	// return success
	return(1);
} // end Draw_Text_GDI

///////////////////////////////////////////////////////////////

int Game_Main(void *parms = NULL, int num_parms = 0)
{
	// this is the main loop of the game, do all your processing
	// here

	// lookup for proper walking sequence
	static int animation_seq[4] = { 0,1,0,2 };
	int index; // general looping variable

	// make sure this isn't executed again
	if (window_closed)
		return(0);

	// for now test if user is hitting ESC and send WM_CLOSE
	if (KEYDOWN(VK_ESCAPE))
	{
		PostMessage(main_window_handle, WM_CLOSE, 0, 0);
		window_closed = 1;
	} // end if

	// copy background to back buffer
	DDraw_Draw_Surface(lpddsbackground, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, lpddsback, 0);

	// move objects around
	for (index = 0; index < 3; index++)
	{
		// move each object to the right at its given velocity
		aliens[index].x++; // =aliens[index].velocity;
		// test if off screen edge, and wrap around
		if (aliens[index].x > SCREEN_WIDTH)
			aliens[index].x = -80;
		// animate bot
		if (++aliens[index].counter >= (8 - aliens[index].velocity))
		{
			// reset counter
			aliens[index].counter = 0;
			// advance to next frame
			if (++aliens[index].current_frame > 3)
				aliens[index].current_frame = 0;
		} // end if
	} // end for index

// draw all the bots
	for (index = 0; index < 3; index++)
	{
		// draw objects
		DDraw_Draw_Surface(aliens[index].frames[animation_seq[aliens[index].current_frame]],
			aliens[index].x, aliens[index].y,
			72, 80,
			lpddsback);

	} // end for index


// flip pages
	while (FAILED(lpddsprimary->Flip(NULL, DDFLIP_WAIT)));

	// wait a sec
	Sleep(30);

	// return success or failure or your own return code here
	return(1);

} // end Game_Main

////////////////////////////////////////////////////////////

int Game_Init(void *parms = NULL, int num_parms = 0)
{
	// this is called once after the initial window is created and
	// before the main event loop is entered, do all your initialization
	// here

	// create IDirectDraw interface 7.0 object and test for error
	if (FAILED(DirectDrawCreateEx(NULL, (void **)&lpdd, IID_IDirectDraw7, NULL)))
		return(0);
	// set cooperation to full screen
	if (FAILED(lpdd->SetCooperativeLevel(main_window_handle,
		DDSCL_FULLSCREEN | DDSCL_ALLOWMODEX |
		DDSCL_EXCLUSIVE | DDSCL_ALLOWREBOOT)))
		return(0);

	// set display mode to 640x480x8
	if (FAILED(lpdd->SetDisplayMode(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, 0, 0)))
		return(0);

	// we need a complex surface system with a primary and backbuffer

	// clear ddsd and set size
	DDRAW_INIT_STRUCT(ddsd);

	// enable valid fields
	ddsd.dwFlags = DDSD_CAPS | DDSD_BACKBUFFERCOUNT;

	// set the backbuffer count field to 1, use 2 for triple buffering
	ddsd.dwBackBufferCount = 1;

	// request a complex, flippable
	ddsd.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE | DDSCAPS_COMPLEX | DDSCAPS_FLIP;

	// create the primary surface
	if (FAILED(lpdd->CreateSurface(&ddsd, &lpddsprimary, NULL)))
		return(0);

	// now query for attached surface from the primary surface

	// this line is needed by the call
	ddsd.ddsCaps.dwCaps = DDSCAPS_BACKBUFFER;

	// get the attached back buffer surface
	if (FAILED(lpddsprimary->GetAttachedSurface(&ddsd.ddsCaps, &lpddsback)))
		return(0);

	// build up the palette data array
	for (int color = 1; color < 255; color++)
	{
		// fill with random RGB values
		palette[color].peRed = rand() % 256;
		palette[color].peGreen = rand() % 256;
		palette[color].peBlue = rand() % 256;

		// set flags field to PC_NOCOLLAPSE
		palette[color].peFlags = PC_NOCOLLAPSE;
	} // end for color

// now fill in entry 0 and 255 with black and white
	palette[0].peRed = 0;
	palette[0].peGreen = 0;
	palette[0].peBlue = 0;
	palette[0].peFlags = PC_NOCOLLAPSE;

	palette[255].peRed = 255;
	palette[255].peGreen = 255;
	palette[255].peBlue = 255;
	palette[255].peFlags = PC_NOCOLLAPSE;

	// create the palette object
	if (FAILED(lpdd->CreatePalette(DDPCAPS_8BIT | DDPCAPS_ALLOW256 |
		DDPCAPS_INITIALIZE,
		palette, &lpddpal, NULL)))
		return(0);

	// finally attach the palette to the primary surface
	if (FAILED(lpddsprimary->SetPalette(lpddpal)))
		return(0);

	// set clipper up on back buffer since that's where well clip
	RECT screen_rect = { 0,0,SCREEN_WIDTH - 1,SCREEN_HEIGHT - 1 };
	lpddclipper = DDraw_Attach_Clipper(lpddsback, 1, &screen_rect);

	// load the 8-bit image
	if (!Load_Bitmap_File(&bitmap, "alley8.bmp"))
		return(0);

	// load it's palette into directdraw
	if (FAILED(lpddpal->SetEntries(0, 0, MAX_COLORS_PALETTE, bitmap.palette)))
		return(0);

	// clean the surfaces
	DDraw_Fill_Surface(lpddsprimary, 0);
	DDraw_Fill_Surface(lpddsback, 0);

	// create the buffer to hold the background
	lpddsbackground = DDraw_Create_Surface(640, 480, 0, -1);

	// copy the background bitmap image to the background surface 

	// lock the surface
	lpddsbackground->Lock(NULL, &ddsd, DDLOCK_SURFACEMEMORYPTR | DDLOCK_WAIT, NULL);

	// get video pointer to primary surfce
	UCHAR *image_buffer = (UCHAR *)ddsd.lpSurface;

	// test if memory is linear
	if (ddsd.lPitch == SCREEN_WIDTH)
	{
		// copy memory from double buffer to primary buffer
		memcpy((void *)image_buffer, (void *)bitmap.buffer, SCREEN_WIDTH*SCREEN_HEIGHT);
	} // end if
	else
	{ // non-linear

	// make copy of source and destination addresses
		UCHAR *dest_ptr = image_buffer;
		UCHAR *src_ptr = bitmap.buffer;

		// memory is non-linear, copy line by line
		for (int y = 0; y < SCREEN_HEIGHT; y++)
		{
			// copy line
			memcpy((void *)dest_ptr, (void *)src_ptr, SCREEN_WIDTH);

			// advance pointers to next line
			dest_ptr += ddsd.lPitch;
			src_ptr += SCREEN_WIDTH;
		} // end for

	} // end else

 // now unlock the primary surface
	if (FAILED(lpddsbackground->Unlock(NULL)))
		return(0);

	// unload the bitmap file, we no longer need it
	Unload_Bitmap_File(&bitmap);

	// seed random number generator
	srand(GetTickCount());

	// initialize all the aliens

	// alien on level 1 of complex

	aliens[0].x = rand() % SCREEN_WIDTH;
	aliens[0].y = 116 - 72;
	aliens[0].velocity = 2 + rand() % 4;
	aliens[0].current_frame = 0;
	aliens[0].counter = 0;

	// alien on level 2 of complex

	aliens[1].x = rand() % SCREEN_WIDTH;
	aliens[1].y = 246 - 72;
	aliens[1].velocity = 2 + rand() % 4;
	aliens[1].current_frame = 0;
	aliens[1].counter = 0;

	// alien on level 3 of complex

	aliens[2].x = rand() % SCREEN_WIDTH;
	aliens[2].y = 382 - 72;
	aliens[2].velocity = 2 + rand() % 4;
	aliens[2].current_frame = 0;
	aliens[2].counter = 0;

	// now load the bitmap containing the alien imagery
	// then scan the images out into the surfaces of alien[0]
	// and copy then into the other two, be careful of reference counts!

	// load the 8-bit image
	if (!Load_Bitmap_File(&bitmap, "dedsp0.bmp"))
		return(0);

	// create each surface and load bits
	int index;
	for (index = 0; index < 3; index++)
	{
		// create surface to hold image
		aliens[0].frames[index] = DDraw_Create_Surface(72, 80, 0);

		// now load bits...
		Scan_Image_Bitmap(&bitmap,                 // bitmap file to scan image data from
			aliens[0].frames[index], // surface to hold data
			index, 0);               // cell to scan image from    

	} // end for index

// unload the bitmap file, we no longer need it
	Unload_Bitmap_File(&bitmap);

	// now for the tricky part. There is no need to create more surfaces with the same
	// data, so I'm going to copy the surface pointers member for member to each alien
	// however, be careful, since the reference counts do NOT go up, you still only need
	// to release() each surface once!

	for (index = 0; index < 3; index++)
		aliens[1].frames[index] = aliens[2].frames[index] = aliens[0].frames[index];

	// return success or failure or your own return code here
	return(1);

} // end Game_Init

/////////////////////////////////////////////////////////////

int Game_Shutdown(void *parms = NULL, int num_parms = 0)
{
	// this is called after the game is exited and the main event
	// loop while is exited, do all you cleanup and shutdown here

	// kill all the surfaces


	// first the palette
	if (lpddpal)
	{
		lpddpal->Release();
		lpddpal = NULL;
	} // end if

 // now the primary surface
	if (lpddsprimary)
	{
		lpddsprimary->Release();
		lpddsprimary = NULL;
	} // end if

 // now blow away the IDirectDraw4 interface
	if (lpdd)
	{
		lpdd->Release();
		lpdd = NULL;
	} // end if

 // return success or failure or your own return code here
	return(1);

} // end Game_Shutdown

// WINMAIN ////////////////////////////////////////////////

int WINAPI wWinMain(HINSTANCE hinstance,
	HINSTANCE hprevinstance,
	LPTSTR lpcmdline,
	int ncmdshow)
{

	WNDCLASSEX winclass; // this will hold the class we create
	HWND	   hwnd;	 // generic window handle
	MSG		   msg;		 // generic message
	HDC        hdc;      // graphics device context

	// first fill in the window class stucture
	winclass.cbSize = sizeof(WNDCLASSEX);
	winclass.style = CS_DBLCLKS | CS_OWNDC |
		CS_HREDRAW | CS_VREDRAW;
	winclass.lpfnWndProc = WindowProc;
	winclass.cbClsExtra = 0;
	winclass.cbWndExtra = 0;
	winclass.hInstance = hinstance;
	winclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
	winclass.hCursor = LoadCursor(NULL, IDC_ARROW);
	winclass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
	winclass.lpszMenuName = NULL;
	winclass.lpszClassName = WINDOW_CLASS_NAME;
	winclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);

	// save hinstance in global
	hinstance_app = hinstance;

	// register the window class
	if (!RegisterClassEx(&winclass))
		return(0);

	// create the window
	if (!(hwnd = CreateWindowEx(NULL,                  // extended style
		WINDOW_CLASS_NAME,     // class
		L"DirectDraw 8-Bit Blitting Demo", // title
		WS_POPUP | WS_VISIBLE,
		0, 0,	  // initial x,y
		SCREEN_WIDTH, SCREEN_HEIGHT,  // initial width, height
		NULL,	  // handle to parent 
		NULL,	  // handle to menu
		hinstance,// instance of this application
		NULL)))	// extra creation parms
		return(0);

	// save main window handle
	main_window_handle = hwnd;

	// initialize game here
	Game_Init();

	// enter main event loop
	while (TRUE)
	{
		// test if there is a message in queue, if so get it
		if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
		{
			// test if this is a quit
			if (msg.message == WM_QUIT)
				break;

			// translate any accelerator keys
			TranslateMessage(&msg);

			// send the message to the window proc
			DispatchMessage(&msg);
		} // end if

		// main game processing goes here
		Game_Main();

	} // end while

// closedown game here
	Game_Shutdown();

	// return to Windows like this
	return(msg.wParam);

} // end WinMain

///////////////////////////////////////////////////////////

